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Studies in humans document the importance of exercise for weight loss and weight management. One study found that as little as 80 minutes of moderate exercise per week was adequate to prevent weight regain after dieting.

The role of exercise in pet weight loss and management is not so compelling. The conventional wisdom is that weight loss success is 60-70 percent diet and 30-40 percent exercise. There is absolutely no research to substantiate these claims. Yet intuitively, we all know that exercise is a good idea for calorie expenditure.

Man and Dog Wanderers

Recent anthropological research suggests that the dog has been man’s best friend for a lot longer than previously thought. In fact, it is speculated that the mutual benefit derived by close association of the two different species influenced the subsequent evolution of both species toward interdependence. One can easily see how the smell and speed of the dog could aid the wandering, hunting style of early man. In return for help with the kill or finding dead carcasses, dogs may have received a more generous share from human pack members than from their food frenzied dog brethren. This ample supply of food would certainly favor a reproductive advantage for dogs in close relationships with humans and vice versa.

Together man and dog wandered large areas to secure an adequate food supply. Anthropologists estimate that Neanderthal men and women burned as much as 5,000 calories daily in this quest. Clearly our metabolic adaptations require we work for our food rather than sit at the drive-thru waiting for it. But what about our faithful companions, wouldn’t the same be true?

Exercise and the Dog

Scientist say the four-legged gait of the dog (as well as cat, chimpanzee and gorilla) is much more efficient than our upright gait. Gravity is also more evenly distributed, so each limb works less against gravity and uses less energy. This means dogs and cats have never worked as hard for their meals as we have. Using exercise to lose weight requires much greater effort for our pets; how much is completely unknown.

What little research we have suggests that a dog must walk at a constant pace of nearly four miles per hour to achieve a significant benefit from exercise. However, few owners are physically capable of providing this level of exercise. Four miles an hour means owners must sweat and dogs must pant. Otherwise it is just a stroll that feels good but does little for either participant. Add the need for 30-60 minutes at this pace for meaningful energy expenditure and it is no wonder that experts put more reliance on diet than exercise.

Adding a weight vest or walking uphill or stairs increases gravitational forces and energy expenditure. This can reduce exercise intensity (speed) and duration. Running obstacle courses or chasing balls and Frisbees is even more intense and can reduce exercise duration.

Exercise and the Cat

Cats are incapable of extended exercise. Their feeding style is short, quick hunting activity, then food consumption, and no activity until the next hunt. They have little stamina. Chase a cat for more than 2-5 minutes and they quickly fatigue, stop, and open mouth breath. Have you ever tried to leash walk with your cat? Yes, some cats will leash train, but they are not breaking land speed or endurance exercise records. They are not athletes. This is why they are easy prey for coyotes and other predators. Prolonged exercise was never a developmental adaptation for the cat.

A Lifetime of Activity

So what is the role of exercise in pet weight loss? There is no question that increased expenditure of calories with restricted intake of calories will promote weight loss and weight maintenance. However, it requires regular commitment on the part of the owner. Walking, running, or Frisbee chasing with dogs requires at least 30-60 minutes a day for 5-7 days a week. Ideally this should be for the entire life of the dog. After all, that is the same recommendation for humans.

Cats need multiple (4-6) periods through the week where they chase a feather toy or laser pointer dot for 2-5 minutes daily. This should also be a lifetime endeavor.

Comments 9

I say "Wow" because my dog, who I've written about before (6 to 7 lbs. overweight) has been undergoing rehabilitation from spinal surgery since October.

He gets two 30 to 40 minute walks per day, plus a daily set of strengthening exercises. He also goes to underwater treadmill (30 minutes) once per week.

I count his calories and limit him to right around 1100 calories per day.

He is currently 92 lbs, but should be 85 or 86 lbs.

His weight hasn't budged ... and that's another reason why I say "Wow," because I really can't understand why his weight hasn't gone down with all this activity. (Thyroid was checked three different times ... "low, but still in normal range" ).

This week I decided to lower his calories to 1050 per day. I hope it helps, but I worry that he's not getting adequate nutrients. (I still need to look into the veterinary diets you mentioned a while ago, too.)

The equation you published a few posts ago indicates that he should have more like 1400 calories per day, but he is 10 years old, so maybe age is a factor, too.

I have looked at the weighted belt for dogs, and am considering it. Since his spinal surgery, ball and Frisbee throwing are now permanently forbidden activities.

Thanks for this great series you're doing about dog and cat weight management!

Your dog should be losing weight on that number of calories. Some dogs with "low normal" thyroid benefit from supplementation; you may want to consult with Dr. Dodds at Hemopet (http://www.hemopet.org/). Also, high-protein is better for weight loss than typical high-carb diets.

1. It's so much easier to keep the dog/cat at a healthy weight to begin with. To that end, vets should always tell clients that their dog/cat's metabolism will drop significantly after spay/neuter. I didn't know that and one of my cats gained a significant amount of weight (5 pounds). We got it off her by 2xdaily short exercise sessions with her feather-on-a-stick and by decreasing her food. It wasn't a happy time for her!

2. I run a breed-specific dog rescue and several times we've had to get 50-75 pounds off of a dog. (These dogs should have weighed in the 90-100 range.)

Each of these dogs had untreated low or low-normal thyroid. We put them on thyroid meds, started with easy strolls, and dropped food to 1/2 cup/day best-quality kibble and lots of green beans.

All of them lost a great deal of weight and continued the weight loss after they were adopted. Happily, they all had normal life spans and didn't seem to have been negatively impacted by the obesity or the weight-loss measures.

I think much more emphasis needs to be placed on examining whether low-normal thyroid needs to be treated.

The comments to today's blogs are great. Forgive me for addressing them all together.

3Dogs: Please do not become despondent. Despite your baby's rehabilitation exercise, it is not a significant calorie burn. We do not have much data on pet energy expenditure during various types of exercise like that in humans. Dr. Ernie Ward in his book "Chow Hounds" suggests that dogs walking @ 4 miles per hour only burn .8 calories per pound of body weight per mile. He does not cite a research reference so I cannot verify those numbers, but it means that your dog is only expending about 150-200 calories per walk if it is at a pace of 15 minute miles. If the pace is more leisurely (you are not sweating and he is not panting) the calorie burn is less. The underwater treadmill is probably only adding another 100-200 calorie burn per week. Most of my weight loss patients receive only 60% of their calculated inactive calorie needs, which is much more than your calorie restriction. These are the probable reasons you are not seeing the results that you would like. But I do not recommend that you mimic my program without veterinary supervision. I freely admit that it will be difficult finding a veterinarian that is well versed in dieting and the nutritional needs of dieters but this is not something that your should try and do on your own.

OldBroad: Actually there is not much scientific evidence that supports metabolism changes dramatically with age. What tends to happen is that we and animals decrease our activity due to aches and pains or other reasons (hiring others to do our household and gardening chores) and we expend less energy to offset our energy intake as we did when we were younger. So what appears to be metabolic changes are merely exercise changes. And with the high calorie content of pet food, feeding the same way as an animal ages can result in weight gain. This isn't much different than the high energy content of our own "fast food" and "ready to eat food". In other words are lifestyles, pets and humans, have changed dramatically and we may be witnessing a cultural change. Most of our grandparents and great grand parents aged without being the weight of ourselves (me included).

TransplantedTexan: You are spot on. 2 of my first 4 weight loss patients were hypothyroid. That is why all of my weight loss patients receive a bloodwork screen to ensure there are no health reasons to preclude dieting and screen for hypothyroidism and Cushing's disease that would make weight loss very difficult.

For all of you I have an upcoming blog on the Green Bean Diet I hope you read. I incorporate green beans in my weight loss programs but there are some nutritional hazards with the present internet recommendations. The problem with nutritional deficiencies is that it may take years to discover the effects. That is why I am so passionate about making sure do-it-yourself homemade diets and raw diets are mathematically nutritionally balanced.

Dr T, we also look forward to seeing your green bean diet for dogs as we are continually asked to foster and may soon take another dog in since loosing our boy.

We had an older fellow who had a poultry allergy that was difficult enough to cater to with commercial foods. On top of this he was 68 pounds when we took him in. With gradual reduction in calories we did manage to get the old dog down to a healthy 40 pounds within a year or so. Part of our strategy was to shrink his stomach by increasing the number of meals per day to four from one. He loved Lean Cuts canned food, and previously the owner had mixed canned in with dry, so the dog felt he had to eat everything in the dish to get the canned food portion - and his stomach had a large capacity for food! The remainder of the strategy was for my husband to walk the dog for a good hour every night that wasn't raining, (we live in a rain forest). Both dog and man were lean and fit. (-: